Study Presented at Plenary Session of American College of Rheumatology (ACR) Meeting

New Orleans -- October 28, 2002 --

Genentech, Inc. (NYSE: DNA), Roche, and IDEC Pharmaceuticals Corporation (Nasdaq: IDPH) today announced preliminary positive interim results from a randomized, double-blind, placebo-controlled Phase II study examining the use of Rituxan® (Rituximab) in the treatment of rheumatoid arthritis (RA). The study, sponsored by Roche, was presented by Jonathan C.W. Edwards, M.D., of University College London during the plenary session of the Annual American College of Rheumatology (ACR) Meeting.

"These data suggest that targeting B-cells with Rituxan may represent a completely new approach to treating patients with rheumatoid arthritis," said Hal Barron, M.D., FACC, Genentech's vice president, Medical Affairs. "We will await final results of this study and will hold discussions with the FDA in anticipation of initiating a global clinical development program, including potential registration Phase III trials and additional Phase II studies during the first half of 2003."

The Phase II study enrolled,161 patients with RA, all of whom were rheumatoid factor positive and receiving methotrexate but not responding. Patients were randomized into one of four treatment groups: one group continued receiving methotrexate alone (at least 10 mg weekly), a second group received Rituxan alone, a third group received Rituxan in combination with cyclophosphamide and a fourth group received Rituxan in combination with methotrexate (at least 10 mg weekly). Rituxan was administered as two intravenous infusions, with doses (1g) given two weeks apart. Each group also received a course of intravenous and oral corticosteroids. Interim data was presented on the first 122 patients at 24 weeks:

According to the authors, the study's safety profile based on the interim data indicates that all three Rituxan regimens were well tolerated with similar levels and type of adverse events occurring when compared to the methotrexate alone arm. The majority of events were infusion reactions of mild or moderate intensity.

"In the five years since receiving FDA approval more than 250,000 patients with non-Hodgkin's lymphoma have been treated with Rituxan worldwide," said Dr. Barron. "We are encouraged by the growing body of data with Rituxan in numerous immunological and autoimmune disorders in which B-cells may play a role. To address the potential utility of Rituxan for these disorders, there are numerous clinical trials currently planned or underway for diseases such as idiopathic thrombocytopenia purpura, hemolytic anemia and lupus, among others."

About RA and B-Cells

RA is a debilitating disease that hinders the daily activities of sufferers. In 2000, there were 5.8 million patients worldwide with RA, a disease with no known cure. RA is characterized by inflammation of multiple joints, cartilage loss and bone erosion that leads to joint destruction and ultimately reduced joint function. Additionally, since RA is a systemic disease, it can have effects in other tissues such as the lungs, eyes and bone marrow. Fewer than 50 percent of patients who have had RA for more than 10 years can continue to work or function normally on a day-to-day basis.

Both genetics and environmental factors are implicated in RA, and there is no known cure. Treatments include a variety of steroidal and non-steroidal anti-inflammatory drugs, immunosuppressive agents, and disease-modifying antirheumatic drugs (DMARDS). All of these treatments target the immune system's T-cells or inflammatory signals.

Until relatively recently it was not known that the immune system's B-cells also are involved in the pathogenesis of progressive RA. However, research in 1987 and 1988 established that B-cells are indeed present and proliferate in the membranes of joints when they are inflamed. While the presence of B-cells in inflamed tissue has not yet been fully elucidated, current data suggests that B-cells may be either a cause or byproduct of RA.

About Rituxan

Rituxan is a chimeric monoclonal antibody that binds to a particular protein - the CD 20 antigen - on the surface of normal and malignant B-cells. It is thought to recruit the body's natural defenses to attack and eliminate the marked B-cells. Stem cells (B-cell progenitors) in bone marrow lack the CD20 antigen, allowing healthy B-cells to regenerate after treatment and return to normal levels within several months.

More than 250,000 patients have been treated with Rituxan worldwide. Rituxan received FDA approval in November 1997 for the treatment of relapsed or refractory low-grade or follicular, CD20 positive, B-cell non-Hodgkin's lymphoma (NHL). It also was approved in the European Union (EU) under the trade name MabThera in June 1998. Genentech and IDEC co-market Rituxan in the United States, Roche markets Rituxan in the rest of the world, except Japan where Rituxan is co-marketed with Zenyaku Kogyo Co. Ltd. In March 2002, the EU approved MabThera and CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) for the treatment of aggressive NHL.

Rituxan Safety Profile

In non-Hodgkin's lymphoma patients based on clinical trials and post-marketing experience, the majority of patients experience infusion-related symptoms with their first Rituxan infusion. These symptoms include, but are not limited to, flu-like fever, chills/rigors, nausea, urticaria, headache, bronchospasm, angioedema and hypotension. These symptoms vary in severity and generally are reversible with medical intervention. In rare instances, severe and fatal infusion-related reactions have occurred, nearly all of which have been associated with the first Rituxan infusion. These events appear as manifestations of an infusion-related complex and include hypoxia, pulmonary infiltrates, acute respiratory distress syndrome, myocardial infarction, ventricular fibrillation, cardiogenic shock and tumor lysis syndrome. Patients who develop clinically significant infusion-related cardiopulmonary events should have their Rituxan infusion discontinued and receive medical treatment.

In rare instances, severe mucocutaneous skin reactions have occurred that may be associated with Rituxan therapy. Many of these reactions have been described as paraneoplastic pemphigus and are known to be associated with various B-cell lymphomas, particularly NHL and CLL. Patients who develop a severe mucocutaneous skin reaction should have Rituxan discontinued and receive appropriate medical treatment including a skin biopsy to guide therapy.

About Genentech

Genentech is a leading biotechnology company that discovers, develops, manufactures and commercializes biotherapeutics for significant unmet medical needs. Fifteen of the currently approved biotechnology products originated from or are based on Genentech science. Genentech manufactures and commercializes ten biotechnology products directly in the United States. The company has headquarters in South San Francisco, California and is traded on the New York Stock Exchange under the symbol DNA.

About Roche

Headquartered in Basel, Switzerland, Roche is one of the world's leading research-oriented healthcare groups in the fields of pharmaceuticals, diagnostics and vitamins. Roche's innovative products and services address prevention, diagnosis and treatment of diseases, thus enhancing people's well being and quality of life

About IDEC

IDEC Pharmaceuticals focuses on the commercialization and development of targeted therapies for the treatment of cancer and autoimmune diseases. IDEC's antibody products act chiefly through immune system mechanisms, exerting their effect by binding to specific, readily targeted immune cells in the patient's blood or lymphatic systems. IDEC is headquartered in San Diego, California, and is traded on the NASDAQ National Market System under the stock symbol, IDPH.